The present invention relates to launching devices for fireworks projectiles and, more particularly, to a launcher for holding and successively launching a plurality of such projectiles.
Pyrotechnic displays, commonly referred to as fireworks or fireworks displays, have been created and enjoyed for centuries by millions of people. Typical systems of the prior art for creating fireworks displays include a pyrotechnic projectile and a mortar for launching the pyrotechnic projectile into the air. Typical pyrotechnic projectiles comprise an inner shell with a main burst that detonates in the air and an initial burst enclosed within an outer shell. By manually igniting an initial fuse, the initial burst is exploded and expels the pyrotechnic projectile from the mortar into the air. This explosion, in turn, lights a main fuse which takes a specific time to burn into and ignite the main burst into an aerial pyrotechnic display.
Typical prior art mortars are cylindrical in shape and are constructed of rigid materials, such as cardboard, metal or plastic. This relatively simple mortar construction requires that the pyrotechnic projectile have a specific orientation within the mortar. The orientation provides for the outer shell having the initial burst to be arranged so that it is below the main burst. When the initial burst is ignited, it explodes and expels the pyrotechnic projectile from the mortar. This explosion produces a loud noise, objectionable quantities of smoke and extremely corrosive agents at the launch site resulting from combustion of the initial burst. Moreover, existing mortar construction generally is not conducive to adjustment after installation at the launch site. As a result, it is difficult and sometimes impossible to change the orientation of the mortar so as to aim the pyrotechnic projectile to different locations in the sky.
Special problems also are encountered when attempting to successively launch pyrotechnic projectiles from the same mortar. This involves loading a first pyrotechnic projectile into the mortar and then lighting the initial fuse at the appropriate time. After this, for safety reasons the mortar site must be cleared before the initial burst explodes. To launch the next pyrotechnic projectile, the operator must return to the mortar and repeat the same process with another pyrotechnic projectile. Hence, constant operator intervention is required and it is not possible to conveniently and quickly launch successive pyrotechnic projectiles from the same mortar. As noted above, problems also exist when it is desired to change the orientation of the mortar from one projectile to the next.
The foregoing problems with prior art mortars were recognized and solved by the inventions disclosed and claimed in U.S. application Ser. No. 817,591 filed Jan. 7, 1992. One of these inventions provides a launching device which uses a remote, non-explosive launching medium to rapidly expel a new type of fireworks projectile into the air. The launcher comprises a pressure tank containing compressed gas and a launching tube having a lower end connected to the pressure tank and an open end for expelling the projectile into the air. A valve connected between the pressure tank and the launching tube is opened and closed to accurately introduce a predetermined amount of compressed gas, at a controlled pressure, from the pressure tank to the launching tube. Upon release, the pressure of the gas rapidly expels the projectile from the open end of the tube. An electronic fuse on the projectile is programmed to detonate the main burst of the projectile at a predetermined time after launch. No initial burst is needed.
In one of the disclosed embodiments of application Ser. No. 817,591, the launcher includes a multiple breech comprising a row of cylindrical tubes containing the projectiles to be launched. Each of the tubes is moved successively into registration with the main launching tube into which the compressed gas is released for launching the projectile. The row of cylindrical tubes can be arranged in a straight row or in a circular or cylindrical manner. An appropriate means may be provided for indexing the tubes such that the projectiles can be launched in succession at a predetermined time or rate.
Notwithstanding the improvements in launching devices provided by the compressed gas launcher described above, further versatility still is desired. For example, it is desirable to ensure that the launching barrels containing the projectiles will not inadvertently advance while the pressure tank is pressurized. It also is desirable for safety reasons to ensure that the main burst of the projectile will not accidentally or inadvertently detonate before the valve opens for launching. In addition, it would be desirable to have the ability to change the launching angle of the various launching tubes once they have registered for firing.
Accordingly, there has existed a need for a device for successively launching and detonating fireworks projectiles, in which the launching angle can be controlled and varied for each launching tube, and which prevents accidental or inadvertent firing of a projectile from the wrong launching tube. The present invention satisfies these and other needs, and provides further related advantages.